FR2808609A1 - Monitoring system for elderly person includes activity sensor and physiological sensor combined to initiate warning of fall - Google Patents

Abstract

The system for detection of a possible fall by a person includes a device for detecting activity, or lack of activity, of the person. The significance of this information is confirmed by a further detector sensing a physiological parameter, such as pulse, arterial pressure, breathing rate or temperature. When both of these sources of information indicate abnormal conditions, an alarm signal is generated. The system for detection of a possible fall by a person includes a device for detecting a potentially abnormal situation. This may be provided by one, or preferably two accelerometers providing a signal indicating the activity, or lack of activity, of the person. The significance of this information is confirmed by a further detector sensing a physiological parameter, such as pulse, arterial pressure, breathing rate or temperature. When both of these sources of information indicate abnormal conditions, an alarm signal is generated and this is transmitted to a remote position in order to call for assistance.

Description

Device and method for detecting abnormal situations The field of the invention is that of the detection of certain abnormal situations, in particular pathological situations, and in particular falls, in a human subject. Such detection is intended in particular to transmit an alarm to a third person (natural person or services, ...) performing a remote monitoring function.

The invention can find applications in many situations, and can in particular equip elderly and / or reduced mobility, isolated workers, children, animals, ...

Known telearm systems generally consist of an assembly carried by the subject and connected to a fixed base, for example by an HF link. In an abnormal situation, the fixed base transmits a coded message, for example carried by the telephone network, to a specialized center. In some institutions, the message can be conveyed by an internal network.

In all cases, these systems provide for a posteriori and voluntary triggering of the process, following a fall or a malaise. This implies that the subject has the capacity and the will to do so.

Various remote alarm systems are already known. In particular there are devices carried in the form of medallion around the neck, require a clamping action or traction to issue an alarm. Besides the fact that they are passive systems (requiring a voluntary voluntary action), these devices often produce false alarms, for example at night, when they are worn and cling inadvertently in the bedding. Moreover, we do not know when they are not worn.

Motion sensors are also known, providing information on the abnormal nighttime activity, or position sensor systems equipping the beds in certain medical services.

In fact, to describe a fall from the center of gravity of a person, it is necessary to be able to establish the kinematics, that is to say to know the initial conditions (mass, size, position), the three accelerations and the three rotations. Such a solution is proposed in the French patent document FR-2760116 which uses two gyrometers. The trajectory is calculated, and an inclinometer informs of the end of the movement.

It can be carried in a pocket, but it has a significant consumption, which is a limiting factor of its use for a person in isolated site. In addition, it can detect only significant falls, is not a "micro fall" on the patient's bed, or a slow fall, for example along a wall. We know that a dependent person, physically limited in his movements, seeks support along his route. Similarly in sitting or lying down, discomfort will not be followed by an alarm.

Systems combining the deceleration detection during a fall and a bidirectional voice channel, systems combining the protection with respect to verticality and the evaluation of the kinetic energy of the human body and systems combining an analysis of actimetry and a position sensor.

In general, these different techniques are not 100% effective, but only able to detect significant falls, with varying degrees of accuracy. It has two major drawbacks - not all Shiites or discomforts are systematically detected, especially when the subject is sitting or lying down; - they produce a large number of false alarms.

Also known non-ambulatory monitoring sets, capable of transmitting measurements of certain physiological parameters. The most sophisticated use telemedicine. is complex and expensive systems, reserved for certain types of patients, but not adapted to elderly and / or reduced mobility in isolated site.

We still know different types of physiological sensors (pulse, breathing, temperature, ...), but they are never associated with decision-making processes, and do not detect an abnormal situation, such as a fall.

The object of the invention is in particular to overcome various disadvantages of the prior art.

More specifically, an object of the invention is to provide a device and a method for detecting abnormal situations, in particular falls which have an optimum reliability (that is to say close to 100%). In particular, the invention aims to allow the detection of all types of falls, even when the subject is bedridden or sitting, or has the body leaning against a wall.

Another object of the invention is to provide such a device and such a method eliminating, or at least strongly limiting, the generation of false alarms (due for example to a sudden movement, to an untimely shock, <B> .. </ B>).

In other words, the object of the invention is to enable detection of abnormal situations which are both safer and more effective than known techniques.

Furthermore, an object of the invention is to provide such a device which is relatively simple and inexpensive to manufacture; - which has a low consumption, and therefore a good autonomy; - space-saving, and ergonomic (that is to say, it presents no discomfort to the wearer). These objectives, as well as others which will appear as a result, are achieved according to the invention with the aid of a device for detecting abnormal situations, in particular falls, in a living subject, comprising means for generating a alarm signal representative of an abnormal situation, based on an analysis of at least one activity information and, at least in some cases, at least one physiological information. Thus, according to the invention, an efficient and accurate determination of abnormal situations is obtained, taking into account two types of information.

Of course, it is possible that, in certain situations, the activity information is sufficient (sudden drop, for example). In this case, it is not mandatory to take into account the physiological information. Conversely, it can be expected that physiological information is periodically recorded and analyzed, even in the absence of alarming activity information.

Advantageously, the device of the invention comprises - means for detecting a potential abnormal situation, powered by an actimetric system delivering the one or more activity information; and means for confirming said potential abnormal situation, fed by at least one physiological sensor delivering said physiological information.

As noted above, it may be just one mode of using the activity and physiological information, among many.

Preferably, in continuous mode, only the said actimetric sensor (s) are active, and the one or more said physiological sensors are activated at regular intervals and / or in the presence of a potential abnormal situation.

This approach makes it possible to produce systems with low consumption, the physiological information being obtained and analyzed only when it is necessary to remove a doubt. In steady state, only activity information is tracked.

According to a particular embodiment of the invention, said actimetric system comprises at least one accelerometer. advantageously; it implements at least two (classically three) accelerometers, whose outputs are summed to form a single signal of activity, supplying said detection means of a potential abnormal situation.

The data processing is thus simplified, while offering a good efficiency. Preferably, the one or more physiological sensors deliver less one of the information belonging to the group comprising - the pulse; - a size, a function of the arterial pressure; - the rhythm and / or the respiratory rate; the temperature, and the variations and / or combinations of these quantities.

Most of this data can be deduced from the signal delivered a single pressure sensor. Thus, advantageously, the device of the invention implements at least one piezoelectric sensor sensitive to the variation of the arterial pressure of said subject.

Advantageously, the device of the invention comprises means for measuring an information representative of the force of application of said device on the skin of said subject.

According to a preferred embodiment, it is made in the form of a wristwatch. We then have a practical and discreet device. Advantageously, the device of the invention comprises a probe, or piston, forming an interface between the skin of said subject and at least one physiological sensor. This makes it possible to overcome the problems caused by displacement of the bearing area on the wearer's skin.

According to an advantageous aspect of the invention, the device comprises means for generating a local alarm and means for transmitting to a remote site of said alarm, after a predetermined delay, when said alarm has not been manually disabled by said subject.

Thus, it avoids the transmission of false alerts to a remote management site. It is the wearer who himself manages the false alarms. Advantageously, the device further comprises manual triggering means, emitting an alarm to a remote site. The wearer can thus, even in the absence of automatic detection, notify the surveillance site, for example in case of discomfort or warning signs of the latter. According to a preferred embodiment, said manual trigger is obtained by strongly pressing on said device, so as to act said measuring means of information representative of the application force.

The implementation is then very simple, and requires no additional means.

Advantageously, the device of the invention comprises means for storing at least one fall model and / or a series of said physiological measurements.

Preferably, means are provided for displaying at least one of the information belonging to the group comprising - time and date; - physiological information; - alerts; - personalized messages, at a given moment; - location information.

The device may also comprise at least one photodiode, for transmitting information to processing means of said device and / or for delivering illumination information.

. The abnormal situation detection device can also set a microphone, be associated with an anti-fugue system, include locating means and / or physiological monitoring means. The invention also relates to the method implemented by the device described above. This method includes a step of generating an alarm signal representative of an abnormal situation, based on an analysis of at least one activity information and, at least in some cases, at least physiological information.

Preferably, the method comprises the following steps: detection of a potential abnormal situation, as a function of the one or more activity information; and - confirmation or denial of said potential abnormal situation, depending on the one or more physiological information.

Advantageously, it also comprises the following steps: generation of a local alarm; waiting for a cancellation command by said subject for a predetermined period of time; - transmission to a remote site of said alarm, when said alarm has not been canceled during said delay.

Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment of the invention, given by way of a simple illustrative and limiting example, and the appended figures among which: FIG. 1 is a general block diagram illustrating the principle of the invention in the case of a fall; FIG. 2 is an example of signals delivered by the accelerometers in the event of a fall, and of their addition; FIG. 3 shows the principle of transferring the cardiac pulse to the device of the invention, produced in the form of a wristwatch - FIGS. 4a and 4b show an example of heartwaves modulated by respiration, respectively in the field temporal and in the frequency domain; FIG. 5 is a block diagram showing the functionalities of the device of the invention; FIG. 6 shows the various sensors and their environment implemented during the device of the invention; - Figure 7 shows, in section, an embodiment of the device of the invention; FIG. 8 is a detailed flowchart of the monitoring method of the invention. The invention therefore relates to a device for detecting abnormal situations in a subject, including falls. This device, and the corresponding method, are more reliable and more accurate than the known systems in particular because they combine, at least when necessary, actimetric and physiological information, as is illustrated by the general synoptic of Figure 1.

The analysis of the actimetric situation of the patient, according to the information delivered by actimetric sensors 12 can be of three normal types 111: only the actimetric sensors are then in function; clearly abnormal 112: in this case we go directly to step 13 of generating an alarm; - potentially abnormal 113: this is the usual case where a significant movement has been detected, without being sure that it is a fall (this case is even more frequent than the thresholds of detection of movement are weak, so as to detect "micro falls").

In the latter situation 113, it implements an additional step 14 of confirming or invalidating the normality of the situation, according to actimetric information 16. If the wearer can move, he can manually trigger an alarm. In the opposite case, the physiological information 15 is taken into account. In case of denial, the normal situation 111 is found. Otherwise, the step of generating an alarm is carried out. Of course, the physiological data can be measured regularly, independently of a motion detection, and if necessary cause the emission of an alarm, for example in the event of a heart problem (even if it does not occur). there was no fall ...).

The actimetric and physiological information can also be used in parallel, or in any other suitable way.

According to another advantageous aspect of the invention, the generation of alarms 13 is done in two stages, so as to avoid the generation of false alarms and therefore the useless interventions of the persons in charge of the remote surveillance. Thus, a local alarm 131 is first generated, for example in the form of a sound signal.

The carrier subject then has a predetermined period of time, for example a few tens of seconds, to intervene, and cancel the alarm if it is really in a situation requiring intervention. when the alarm is canceled (132), the normal mode is returned. In the opposite case an alarm transmitted, (133) to the remote monitoring site.

Advantageously carried in the form of a watch case, the device of the invention therefore comprises a set of traction sensors, which makes it possible to know the accelerations of the wrist. These magnitudes, an example of which is given in FIG. 2 (21, 22 and 23: accelerations respectively along the X, Z and Y axes) therefore serve, in the foreground, to discriminate a critical energy level. In fact, the bandwidth of accelerations during a fall is between 0.5 Hz and 6 Hz, considered as a narrow band.

To optimize consumption, assimilates the rectified signals 21, 22 and 23 added and low-pass filtered to the energy involved, to obtain the signal 24, which serves to awaken the calculation means of the device.

In the following seconds, energy measurements are made and compared to a fall model, according to the algorithm described later.

This fall can be relative, that is to say that the center of gravity of the human body remains almost invariant. In this case, the comparison can be tricky. It is for this reason that we will then observe the evolution of certain physiological parameters (pulse, respiration, ...) as an indicator of an abnormal situation. As illustrated in FIG. 3, the watch-case device 31 is held on the wrist with the aid of an elastic strap 32, similar to that of a conventional watch. The cardiac pulse 33 passes through the vessels 34, the muscle, the tissues 35 and the skin and then propagates through the bracelet 32, which generates a stress on a sensor 36, described in more detail below. Thus the physiological parameters accessible at the level of the wrist are the image of the cardiac pulse, of which FIGS. 4a and 4b respectively give the temporal trace and the corresponding spectral analysis of a cardiac wave modulated by respiration, in the case sinus arrhythmia male subject of 35 years. these signals, one deduces the pulse and the respiratory rate, and if necessary the arterial tension. By placing a temperature probe very close to the skin, it also obtains the local temperature (biased with respect to the temperature of the human body) from which the variation of temperature is deduced. Without any movement, these parameters are memorized, the system realizing its self-learning.

After a fall or discomfort, the subject may be physically immobilized. In this case, the temperature of his body drops. This parameter can be discriminating if the change in body temperature is significant for a sufficiently long time.

The history of the physiological parameters is retrieved after the fall, in the event that it is not detected immediately (potential abnormal situation). In fact, it is a function of the pathology that caused the fall. However, if the person is blocked, we can find the following variations - pulse: bradycardia or tachycardia; - breathing: increasing frequency, following the state of stress then regularizing, then observation of respiratory pauses; - blood pressure: may vary in one direction or the other (increase or decrease depending on the cause); - temperature variation: by extrapolating the body reaction of a person in a sleep situation to that of a person immobilized, and knowing that man is an endotherm since only his internal temperature is constant, it can be argued that the mechanism thermoregulation ensures the maintenance of this endothermie despite ambient conditions that can be very variable. However, the skin temperatures are not uniform: the lowest temperatures are often those of hands and feet (28 to 31) when the temperature of the highest head, is of the order of 34 to 35.

Figure 5 illustrates the main features of the device of the invention. continuous regime, only the actimetric means 51 are active. The microcontroller is dormant, as well as the HF transmitter. Intermittently, measurements are made of the heart rate (Fc) and respiratory rate (Fr) and temperature, and respective amplitudes, which are stored (53) to follow the evolution of these quantities, and for possible to be able to affirm that the subject is no longer normal situation.

If the motor level is exceeded (shake deduction 54), the microcontroller is awake (55), and an acquisition is started, which is intended to pick up the traction signals and to detect if there has been a fall (56), from a stored algorithm (53).

Then the previous physiological parameters are acquired (58) during, for example 30 seconds, calculations are performed is exceeded test operated.

Then, a shake test 55 is implemented, to verify that the wearer can move. In this case, a manual triggering of the alarm is possible, as well as an alarm transmission when the device is worn or not properly tightened.

Alarm <B> 510 </ B> is transmitted via transmission means HF 52. Advantageously, the transmission specifies the type of alarm - watch not worn; - deficient clamping; - physiological parameters outside the threshold; - fall; - manual triggering.

 Figure 6 shows the environment of the sensors used. The three accelerations are captured by an integrated or modular 3D accelerometer 61, for example of the ACH 04-08-05 type manufactured by the company AMP (registered trademark) or any equivalent type, having a sensitivity of 2 mV / g in the bandwidth 0.5 HZ-OHZ. They are followed by a summator 62 (see figure of a gain amplification 50 and a thresholding 63 in the corresponding bandwidth.

The detection of the cardiac pulse is carried out using a piezoelectric sensor 64, having the shape of a disk (diameter <I> 0 = </ I> 16 mm, e = 0 mm) using the direct piezoelectric effect (material PZT PIC 155, built by PI CERAMIC (registered trademark)). The value of the capacity for 1 Hz is 8.65 nF. Loaded under equal capacity in parallel, with a resistive load of 33 MSZ, the cutoff frequency is 0.6 Hz and the sensitivity of 54 mV / N. a transimpedance stage provides the connection with a gain amplifier 500 and a 0.5-3 Hz bandwidth for a cardiac pulse delivering 1/100 of N at the sensor, a peak-to-peak amplitude signal is obtained at the output. 400 mV.

This sensor can also give the image of the acceleration along the Z axis.

The operational amplifiers used are of the very low consumption type, and for example MAX 418 amplifiers of the company MAXIM (registered trademark).

The tightening of the bracelet is detected by a resistive sensor 65 of type FSR 152-NS, flat semiconductor sensor covered with a polymer. Integrated into an operational amplifier stage, it is possible to discriminate in output 4 levels which are - greater than 1 V: watch not worn; between 0.15 V and 0.9 V: worn watch; - less than 0.09 V: very strong tightening, performed deliberately and which serves as a button for the manual alarm.

It should be noted that each of the beaches is separated from its neighbor by a blank zone, which makes it possible to secure the analysis. To improve the detection of the presence of the manual alarm, a level stability test is performed.

You can also use a Motorola (trademark) MX 2300 sensor, which improves situation discrimination.

The temperature sensor 66 may be a LM 62 semiconductor sensor manufactured by National Semiconductor (registered trademark). Its resolution is 0.2. It is advantageously in the probe, or piston, separated from the skin by about 1 mm.

The photodiode sensor 67, for example of the BPW 34 type of SIEMENS (registered trademark), serves to transmit information by means of calculations 681 (initialization, tests, etc.), and can also inform about the ambient illumination.

The microcontroller 68 can be broken down, functionally, into - interrupt management means 682, powered by the actimetric information and the bracelet tightening information - measurement and calculation means 681 powered by actimetric information, clamping, pulse pressure, temperature and photodiode; storage means 683; alarm management means 684.

The alarm management means 684 act on the RF transmitter to emit the alarm 691, for example to a fixed base.

Figure 7 describes the assembly of the various sensors and electronics integrated in the watch case, in section.

A piston 71 is provided to come into contact with the skin of the carrier subject. It contains the temperature probe 72. A membrane 73, glued to the piston 71, ensures the transfer of the cardiac pulse, allowing a variation of perpendicularity between the piston 71 and the sensors. The connection between the sensors and the piston is made by silicone gel 75, mechanically decoupling the assembly. The piezoelectric cardiac pulse sensing sensor 76 is stuck on the wrist strap sensor 74. Thus, there is preload on the piezoelectric material, allowing the detection of small pulses.

The electronics consist of printed circuits 77 and 78. Of course, it can be reduced to a single printed circuit. The display of the time, and any other information, is returned by the display 79, for example of the liquid crystal type. The alarms are conveyed via the transmitter 710 and the antenna 711. The on-board power source is a battery 712, providing autonomy for more than one year to the device. The latter is held on the wrist by an elastic bracelet not shown.

The sealing means are also not representative, but are chosen so as to ensure a sealing runoff. The materials used and which are in contact with the skin are not offensive and more generally not dangerous for permanent wear of the watch.

The electronics comprises two main functions, which are the environment of the sensors (already described in connection with FIG. 6) the calculation and transmission means. The on-board calculation means can be produced by very low consumption microcontrollers of the Texas Instruments family (registered trademark) or the XEMICS XE 88xx family (registered trademark). These microcontrollers have analog measurement means with good accuracy (greater than 12 bits), time bases, display drivers for liquid crystals (display of the time and certain alarms) a sufficient program memory, and digital links with an FM type FM transmitter whose range is 60 m with free field.

Before describing the surveillance algorithm in more detail, the following three points are recalled - the false triggering of false alarms is a major problem for any automatic detection system. A system generating a high false alarm rate will be a system quickly abandoned. To avoid this inconvenience, alarm with automatic triggering will be systematically validated, under a certain delay, by the carrier, before being diffused. The expiration of this period will inevitably lead to the broadcast of the alarm, this suggests that the wearer is unable to react and is therefore in difficulty. It is therefore the system carrier who must bear the false alarms, and not the emergency service; - a fall followed by inactivity is an alarming situation. This aspect is integrated for the final decision-making (alert or non-alert); - autonomy is a crucial parameter for an ambulatory system. It was therefore taken into account from the outset of the design of the device. Monitoring signals from accelerometers is provided by an analog device low consumption. The role of this device is to reactivate, in the case of a threshold exceeding (activity considered potentially abnormal), the microcontroller managed in sleep / wake mode thus avoiding unnecessary consumption. An analysis of the parameters is then carried out to determine whether the situation is critical or not. The monitoring of physiological parameters is carried out periodically so as to detect any anomaly.

Figure 8 illustrates the monitoring flowchart implemented.

In normal and continuous situation, it is in the passive monitoring mode 81 by the analog device. The microcontroller is in standby 811. The motricity 812 is monitored, and it remains in this mode as long as there is no significant movement detected 813.

At regular intervals, cyclic monitoring 82 of physiological parameters is employed. As long as these parameters are normal (821), no action is taken.

When a large movement (813) has been detected, active monitoring mode 84 is switched to by the analog device. The microphone (841) is awakened, then the activity (842) is appreciated. If the activity is considered normal (843), it returns to the passive monitoring mode. In the opposite case, one passes followed by the activity (844), taking into account the physiological parameters (822). If there is a finding of inactivity, it goes to the system mode alarm 85. Otherwise, we check (846) if the activity is normal. If the answer is negative, it returns to the step (844) of monitoring the activity. Otherwise, the microphone returns to standby (811).

The alarm mode first comprises a local alarm (851), including the setting of a timer. If in the duration of this delay, the alarm is deactivated (852), it returns to the normal situation and the microphone returns to standby (811). Otherwise, an alarm is transmitted (853) after the timer expires. After acknowledgment (854) of the alarm, the microphone returns to standby (811).

One can, of course, provide many variants, complement and / or option to the device of the invention.

In particular, the display can be used, for example by liquid crystals, to display information such as time, personalized messages (taking medication, appointments, activities, ...).

Moreover, since the bandwidth of the RF transmitter is sufficient, a microphone can be integrated into the watch to transmit the voice. It is also possible to provide means for receiving voice or other information.

An anti-fugue system can be realized, for example by transmitting an RF signal every fifteen minutes. A pass detection function can also be integrated via the photodiode, since the passage to be detected is equipped with a light emitter. The cyclic transmission of the signal can also make it possible to monitor the quality of the transmission, and thus to secure the system.

The continuous knowledge of the pulse, the temperature and the tightening of the bracelet, if one uses a linear pressure sensor of the respiratory parameters, allow to realize a system of home monitoring, in the form of a system friendly outpatient.

 Lastly, it is possible to combine locating means (GPS) and / or the basic functions of a mobile telephone, to increase distance autonomy and / or to constitute an absolute anti-fugue system.

Claims (9)

1. Device for detecting abnormal situations, especially falls, in a living subject, characterized in that it comprises means for generating an alarm signal representative of an abnormal situation, according to an analysis of at least one activity information and, at least in some, at least one physiological information. 2. Device for detecting abnormal situations according to claim 1, characterized in that it comprises - means for detecting a potential abnormal situation, powered by an actimetric system delivering the one or more activity information; and means for confirming said potential abnormal situation, fed by at least one physiological sensor delivering said physiological information. 3. Device for detecting abnormal situations according to claim 2, characterized in that, in continuous mode, only the said actimetric sensor or sensors are active, and in that the or said physiological sensors are activated at regular intervals and / or in the presence a potential abnormal situation. 4. Device for detecting abnormal situations according to any one of claims 2 and 3, characterized in that said actimetric system comprises at least one accelerometer. 5. Device for detecting abnormal situations according to claim 4, characterized in that it implements at least two accelerometers, whose outputs are summed to form a single signal of activity supplying said detection means of a potential abnormal situation. 6. Device for detecting abnormal situations according to any one of claims 2 to 5, characterized in that the or said physiological sensors deliver at least one of the information belonging to the group comprising - the pulse; - a quantity depending on the arterial pressure; - the rhythm and / or the respiratory rate; the temperature, and the variations and / or combinations of these quantities. 7. Device for detecting abnormal situations according to claim 6, characterized in that it implements at least one piezoelectric sensor responsive to the variation of the arterial pressure of said subject. 8. Device for detecting abnormal situations according to any one of claims 1 to 7, characterized in that it comprises means for measuring information representative of the force of application of said device on the skin of said subject. 9. Device for detecting abnormal situations according to any one of claims 1 to 8, characterized in that it is made in the form of a wristwatch. <B> 10. </ B> Device for detecting abnormal situations according to any one of claims 1 to 9, characterized in that it comprises a probe forming an interface between the skin of said subject and at least one physiological sensor. <B> 11. </ B> Device for detecting abnormal situations according to any one of claims 1 to 10, characterized in that it comprises means for generating a local alarm and transmission means to a site remote from said alarm, after a predetermined time, when said alarm has been manually disabled by said subject. 12. Device for detecting abnormal situations according to any one of claims 1 to 11, characterized in that it comprises manual triggering means, transmitting an alarm to a remote site. 13. Device for detecting abnormal situations according to claims 8 and 12, characterized in that said manual trigger is obtained by strongly pressing on said device, so as to act on said means for measuring an information representative of the force of application. An abnormal situation detection device according to any one of claims 1 to 13, characterized in that it comprises means for storing at least one fall model and / or a series of said physiological measurements. An abnormal situation detection device according to any one of claims 1 to 14, characterized in that it comprises display means minus one of the information belonging to the group comprising - time and date; - physiological information; - alerts; - personalized messages, at a given moment; - location information. <B> 16. </ B> Device for detecting abnormal situations according to any one of claims 1 to 15, characterized in that it comprises at least one photodiode, for the transmission of information to processing means of said device and / or to deliver illumination information. Device for detecting abnormal situations according to any one of claims 1 to 16, characterized in that it comprises a microphone. Device for detecting abnormal situations according to any one of claims 1 to 17, characterized in that it is associated with an anti-fugue system. Device for detecting abnormal situations according to the claim characterized in that it comprises locating means. 20. Device for detecting abnormal situations according to any one of claims 1 to 19, characterized in that it comprises physiological monitoring means. 21. A method for detecting abnormal situations, especially falls, in a living subject, characterized in that it comprises a step of generating an alarm signal, representative of an abnormal situation, according to an analysis of less activity information and, at least in some cases, at least one physiological information. 22. The method for detecting abnormal situations as claimed in claim 21, characterized in that it comprises the following steps: detection of a potential abnormal situation, as a function of the one or more activity information; confirmation or denial of said potential abnormal situation, as a function of the one or more physiological information. 23. The method for detecting abnormal situations according to claim 21, characterized in that it comprises the following steps: generation of a local alarm; waiting for a cancellation command by said subject for a predetermined period of time; - transmission to a remote site said alarm, when said alarm has not been canceled during said delay.